Conventionally, provision of reflection preventive treatment on the surface of the glass product has been practiced to prevent loss of fluoroscopic property and light permeability or dazzling due to the reflection of visible light on the surface of a glass plate or other glass product.
There is known, for example, a low refractive index reflection preventive film made by coating a coating liquid comprising a silica sol having a particle size of 5 to 30 nm and a hydrolyzate of alkoxy silane contained in the solvent and cured (Japanese Patent Laid-open Publication No. H8-122501).
In the front glass of an automobile, there is a problem of lowering a driver's visibility of front area by reflection images of inner panel (instrument panel) inside a car and dash board coming into driver's view. This problem is due to the reflection of the light incident from the inner panel and dash board and surroundings thereof upon the surface of the front window glass. The light incident from inner panel and dash board income with quite a high incident angle upon the front window glass and get into the driver's eyes. In order to improve the visibility, reflectivity upon the front window glass at the high incident angle (60.degree. for example) is required to be lowered. With the above low refractive index reflection preventive film it is still insufficient to realize reduction of reflectivity at high incident angle, and it cannot be commented that the visibility is sufficiently high.
An object of the present invention is to provide a glass plate suitable for windows of an automobile having small reflectivity of visible light at high incident angle and improved visibility.